pgsql: Make use of xlog_internal.h's macros in WAL-related utilities.

Make use of xlog_internal.h's macros in WAL-related utilities.

Commit 179cdd09 added macros to check if a filename is a WAL segment
or other such file. However there were still some instances of the
strlen + strspn combination to check for that in WAL-related utilities
like pg_archivecleanup. Those checks can be replaced with the macros.

This patch makes use of the macros in those utilities and
which would make the code a bit easier to read.

Back-patch to 9.5.

Michael Paquier

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/163e29dc380137127cf7e9c23b1596b78ad0ce81

Modified Files
--------------
contrib/pg_standby/pg_standby.c | 24 +++++++-----------------
src/bin/pg_archivecleanup/pg_archivecleanup.c | 22 ++++++++--------------
src/bin/pg_resetxlog/pg_resetxlog.c | 11 +++++------
src/include/access/xlog_internal.h | 19 +++++++++++++------
4 files changed, 33 insertions(+), 43 deletions(-)