powerpc: make __ffs return unsigned long

I'm seeing a build warning in mm/nobootmem.c after removing
bootmem:

mm/nobootmem.c: In function '__free_pages_memory':
include/linux/kernel.h:713:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
  (void) (&_min1 == &_min2);  \
                 ^
mm/nobootmem.c:90:11: note: in expansion of macro 'min'
   order = min(MAX_ORDER - 1UL, __ffs(start));
           ^

The rest of the worlds seems to define __ffs as returning unsigned long,
so lets do that.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Tested-by: NEmil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/bitops.h

@@ -213,7 +213,7 @@ static __inline__ unsigned long ffz(unsigned long x)
 	return __ilog2(x & -x);
 }
 
-static __inline__ int __ffs(unsigned long x)
+static __inline__ unsigned long __ffs(unsigned long x)
 {
 	return __ilog2(x & -x);
 }

arch/powerpc/sysdev/fsl_pci.c

@@ -152,7 +152,7 @@ static int setup_one_atmu(struct ccsr_pci __iomem *pci,
 		flags |= 0x10000000; /* enable relaxed ordering */
 
 	for (i = 0; size > 0; i++) {
-		unsigned int bits = min(ilog2(size),
+		unsigned int bits = min_t(u32, ilog2(size),
 					__ffs(pci_addr | phys_addr));
 
 		if (index + i >= 5)