xfs: remove duplicate ifdefs

when a ifdef is used in the below manner, second one could be considered as
duplicate.

ifdef DEFINE_A
...code block...
ifdef DEFINE_A
...code block...
endif
...code block...
endif

In the xfs code two such patterns were seen. Hence removing these ifdefs.
No functional change is intended here. It only aims to improve code
readability.

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>