infiniband: mlx5: avoid a compile-time warning

The return type of find_first_bit() is architecture specific,
on ARM it is 'unsigned int', while the asm-generic code used
on x86 and a lot of other architectures returns 'unsigned long'.

When building the mlx5 driver on ARM, we get a warning about
this:

infiniband/hw/mlx5/mem.c: In function 'mlx5_ib_cont_pages':
infiniband/hw/mlx5/mem.c:84:143: warning: comparison of distinct pointer types lacks a cast
     m = min(m, find_first_bit(&tmp, sizeof(tmp)));

This patch changes the driver to use min_t to make it behave
the same way on all architectures.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/infiniband/hw/mlx5/mem.c

@@ -81,7 +81,7 @@ void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift,
 		for (k = 0; k < len; k++) {
 			if (!(i & mask)) {
 				tmp = (unsigned long)pfn;
-				m = min(m, find_first_bit(&tmp, sizeof(tmp)));
+				m = min_t(unsigned long, m, find_first_bit(&tmp, sizeof(tmp)));
 				skip = 1 << m;
 				mask = skip - 1;
 				base = pfn;