powerpc/align: Use #ifdef __BIG_ENDIAN__ #else for REG_BYTE

Sparse complains that it doesn't know what REG_BYTE is:

  arch/powerpc/kernel/align.c:313:29: error: undefined identifier 'REG_BYTE'

REG_BYTE is defined differently based on whether we're compiling for
LE, BE32 or BE64. Sparse apparently doesn't provide __BIG_ENDIAN__ or
__LITTLE_ENDIAN__, which means we get no definition.

Rather than check for __BIG_ENDIAN__ and then separately for
__LITTLE_ENDIAN__, just switch the #ifdef to check for __BIG_ENDIAN__
and then #else we define the little endian version. Technically that's
dicey because PDP_ENDIAN is also a possibility, but we already do it in
a lot of places so one more hardly matters.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/align.c

@@ -228,9 +228,7 @@ static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr)
 #else
 #define REG_BYTE(rp, i)		*((u8 *)(rp) + (i))
 #endif
-#endif
-
-#ifdef __LITTLE_ENDIAN__
+#else
 #define REG_BYTE(rp, i)		(*(((u8 *)((rp) + ((i)>>2)) + ((i)&3))))
 #endif