[PATCH] dax: constify second argument of dax_iomap_pmd_fault

[Jérémy Lefaure <jeremy.lefaure@xxxxxxxxxxxx>]

When CONFIG_FS_DAX_PMD is disabled, the second argument of the function
dax_iomap_pmd_fault is not a const pointer. The compiler raises a
warning about that:
fs/dax.c: In function ‘dax_iomap_fault’:
fs/dax.c:1462:35: warning: passing argument 2 of ‘dax_iomap_pmd_fault’
discards ‘const’ qualifier from pointer target type
   return dax_iomap_pmd_fault(vmf, ops);
                                   ^~~
fs/dax.c:1439:12: note: expected ‘struct iomap_ops *’ but argument is of
type ‘const struct iomap_ops *’
static int dax_iomap_pmd_fault(struct vm_fault *vmf, struct iomap_ops *ops)
           ^~~~~~~~~~~~~~~~~~~

Constifying the second argument as it is when CONFIG_FX_DAX_PMD is
enabled fixes this warning.

Fixes: a2d581675d48("mm,fs,dax: change ->pmd_fault to ->huge_fault")
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@xxxxxxxxxxxx>
---
 fs/dax.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/dax.c b/fs/dax.c
index 5ae8b71ebadc..7436c98b92c8 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1436,7 +1436,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
 	return result;
 }
 #else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf, struct iomap_ops *ops)
+static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+			       const struct iomap_ops *ops)
 {
 	return VM_FAULT_FALLBACK;
 }
-- 
2.11.1