microblaze: Fix compilation warning in ext2_find_next_zero_bit

ext2_find_next_zero_bit must be also static if __swab32 is also static.

Warning:
include/asm/bitops.h:369:22: warning: '__fswab32' is static but
used in inline function 'ext2_find_next_zero_bit'
which is not static [enabled by default]

Signed-off-by: Michal Simek <monstr@monstr.eu>
Acked-by: Stephan Linz <linz@li-pro.net>

arch/microblaze/include/asm/bitops.h

@@ -319,7 +319,8 @@ extern __inline__ int ext2_test_bit(int nr, const volatile void * addr)
 #define ext2_find_first_zero_bit(addr, size) \
 	ext2_find_next_zero_bit((addr), (size), 0)
 
-extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
+static inline unsigned long ext2_find_next_zero_bit(void *addr,
+				unsigned long size, unsigned long offset)
 {
 	unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
 	unsigned long result = offset & ~31UL;