ubifs: Change value of mutex_is_locked()

The mutex lock and unlock functions are stubbed out and mutex_is_locked
was 0.  This caused asserts to fail in ubifs code when checking that the
mutex was locked.  For example,

UBIFS assert failed in ubifs_change_lp at 540
UBIFS assert failed in ubifs_release_lprops at 278

Assume that the "mutex" is locked since that is the normal case when it
is checked in the ubifs code.
Signed-off-by: NBradley Bolen <bradleybolen@gmail.com>

fs/ubifs/ubifs.h

@@ -611,7 +611,7 @@ static inline ino_t parent_ino(struct dentry *dentry)
 /* misc.h */
 #define mutex_lock_nested(...)
 #define mutex_unlock_nested(...)
-#define mutex_is_locked(...)	0
+#define mutex_is_locked(...)	1
 #endif
 
 /* Version of this UBIFS implementation */