cmake: s/STEQUAL/STREQUAL/

Summary:
Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/1540

Differential Revision: D4207564

Pulled By: siying

fbshipit-source-id: 567415b

CMakeLists.txt

@@ -43,10 +43,10 @@ else()
     add_definitions(-DROCKSDB_JEMALLOC)
     include_directories(${JEMALLOC_INCLUDE_DIR})
   endif()
-  if(CMAKE_SYSTEM_NAME STEQUAL "FreeBSD")
+  if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
     # FreeBSD has jemaloc as default malloc
     add_definitions(-DROCKSDB_JEMALLOC)
-    set(WITH_JEMALLOC, ON)
+    set(WITH_JEMALLOC ON)
   endif()  
   option(WITH_SNAPPY "build with SNAPPY" OFF)
   if(WITH_SNAPPY)