changed try_ffi to take trailing comma and updated rustfmt accordingly

rustfmt.toml

@@ -1,3 +1,4 @@
 reorder_imports = true
 max_width = 100
 ideal_width = 100
+trailing_comma = always

src/backup.rs

@@ -52,7 +52,7 @@ impl BackupEngine {
         };
 
         let be: *mut ffi::rocksdb_backup_engine_t;
-        unsafe { be = ffi_try!(ffi::rocksdb_backup_engine_open(opts.inner, cpath.as_ptr())) }
+        unsafe { be = ffi_try!(ffi::rocksdb_backup_engine_open(opts.inner, cpath.as_ptr(),)) }
 
         if be.is_null() {
             return Err(Error::new("Could not initialize backup engine.".to_owned()));

src/db.rs

@@ -618,7 +618,7 @@ impl DB {
 
         if cfs.len() == 0 {
             unsafe {
-                db = ffi_try!(ffi::rocksdb_open(opts.inner, cpath.as_ptr() as *const _));
+                db = ffi_try!(ffi::rocksdb_open(opts.inner, cpath.as_ptr() as *const _,));
             }
         } else {
             let mut cfs_v = cfs.to_vec();
@@ -652,8 +652,7 @@ impl DB {
                     cfs_v.len() as c_int,
                     cfnames.as_mut_ptr(),
                     cfopts.as_mut_ptr(),
-                    cfhandles.as_mut_ptr(),
-                ));
+                    cfhandles.as_mut_ptr(),));
             }
 
             for handle in &cfhandles {
@@ -716,7 +715,7 @@ impl DB {
     pub fn destroy<P: AsRef<Path>>(opts: &Options, path: P) -> Result<(), Error> {
         let cpath = CString::new(path.as_ref().to_string_lossy().as_bytes()).unwrap();
         unsafe {
-            ffi_try!(ffi::rocksdb_destroy_db(opts.inner, cpath.as_ptr()));
+            ffi_try!(ffi::rocksdb_destroy_db(opts.inner, cpath.as_ptr(),));
         }
         Ok(())
     }
@@ -724,7 +723,7 @@ impl DB {
     pub fn repair<P: AsRef<Path>>(opts: Options, path: P) -> Result<(), Error> {
         let cpath = CString::new(path.as_ref().to_string_lossy().as_bytes()).unwrap();
         unsafe {
-            ffi_try!(ffi::rocksdb_repair_db(opts.inner, cpath.as_ptr()));
+            ffi_try!(ffi::rocksdb_repair_db(opts.inner, cpath.as_ptr(),));
         }
         Ok(())
     }
@@ -735,7 +734,7 @@ impl DB {
 
     pub fn write_opt(&self, batch: WriteBatch, writeopts: &WriteOptions) -> Result<(), Error> {
         unsafe {
-            ffi_try!(ffi::rocksdb_write(self.inner, writeopts.inner, batch.inner));
+            ffi_try!(ffi::rocksdb_write(self.inner, writeopts.inner, batch.inner,));
         }
         Ok(())
     }

src/ffi_util.rs

@@ -34,7 +34,7 @@ pub fn opt_bytes_to_ptr(opt: Option<&[u8]>) -> *const c_char {
 }
 
 macro_rules! ffi_try {
-    ( $($function:ident)::*( $( $arg:expr ),* ) ) => ({
+    ( $($function:ident)::*( $( $arg:expr,)* ) ) => ({
         let mut err: *mut ::libc::c_char = ::std::ptr::null_mut();
         let result = $($function)::*($($arg),*, &mut err);
         if !err.is_null() {