autoconf: Remove use of m4_ifblank.
authorCorey Farrell <git@cfware.com>
Sat, 2 Dec 2017 21:55:31 +0000 (16:55 -0500)
committerCorey Farrell <git@cfware.com>
Sat, 2 Dec 2017 21:59:31 +0000 (16:59 -0500)
commit39939cecfa5b2fbdeedbf1cabf32c4907ef4aaf4
treeee8a2d0648511aa86fe998ac73e7e1bc1a777c3a
parent075faac2fd74a79b4f418d1d02a864383b076d05
autoconf: Remove use of m4_ifblank.

The m4_ifblank macro is not available on CentOS 6, reverse conditionals
to allow use of m4_ifval instead.  ./bootstrap.sh was run but this patch
does not result in any difference to the generated configure script.

Change-Id: I280785deb872ed8d3339d99cce63a2b54d5f1438
autoconf/ast_check_pwlib.m4
autoconf/ast_ext_lib.m4
autoconf/ast_gcc_attribute.m4