Revert "Update MDB_PANIC description" (thinko).

This reverts commit 6bd34d0534.

libraries/liblmdb/lmdb.h

@@ -380,7 +380,7 @@ typedef enum MDB_cursor_op {
 #define MDB_PAGE_NOTFOUND	(-30797)
 	/** Located page was wrong type */
 #define MDB_CORRUPTED	(-30796)
-	/** Update of meta page failed, or environment had fatal error */
+	/** Update of meta page failed, probably I/O error */
 #define MDB_PANIC		(-30795)
 	/** Environment version mismatch */
 #define MDB_VERSION_MISMATCH	(-30794)

libraries/liblmdb/mdb.c

@@ -1188,7 +1188,7 @@ static char *const mdb_errstr[] = {
 	"MDB_NOTFOUND: No matching key/data pair found",
 	"MDB_PAGE_NOTFOUND: Requested page not found",
 	"MDB_CORRUPTED: Located page was wrong type",
-	"MDB_PANIC: Update of meta page failed, or environment had fatal error",
+	"MDB_PANIC: Update of meta page failed",
 	"MDB_VERSION_MISMATCH: Database environment version mismatch",
 	"MDB_INVALID: File is not an MDB file",
 	"MDB_MAP_FULL: Environment mapsize limit reached",