xfstests: fix NIS detection damage

NIS detection wasn't tested on machines without NIS enabled, so many tests are
failing on non-NIS machines. the _yp_active function has no specific return
value so always evaluates as 0 (active) and the "_cat_passwd" function is
called from within an awk script which is not valid as the shell may run with a
sanitised environment. Hence the functions do not need specific export calls,
either, as unsanitised subshells will automatically inherit the parent's
environment.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

common.rc

@@ -800,13 +800,14 @@ _yp_active()
 	local dn
 	dn=$(domainname 2>/dev/null)
 	test -n "${dn}" -a "${dn}" != "(none)"
+	echo $?
 }
 
 # cat the password file
 #
 _cat_passwd()
 {
-	[ _yp_active ] && ypcat passwd
+	[ $(_yp_active) -eq 0 ] && ypcat passwd
 	cat /etc/passwd
 }
 
@@ -814,10 +815,9 @@ _cat_passwd()
 #
 _cat_group()
 {
-	[ _yp_active ] && ypcat group
+	[ $(_yp_active) -eq 0 ] && ypcat group
 	cat /etc/group
 }
-export -f _yp_active _cat_passwd _cat_group
 
 # check for the fsgqa user on the machine
 #