MDEV-5436 mysql_config returns non-zero when running without parameters

scripts/mysql_config.pl.in

@@ -258,7 +258,7 @@ Options:
         --version        [$version]
         --libmysqld-libs [$embedded_libs]
 EOF
-  exit 1;
+  exit 0;
 }
 
 @ARGV or usage();

scripts/mysql_config.sh

@@ -176,7 +176,7 @@ Options:
                 pkglibdir     [$pkglibdir]
                 plugindir     [$plugindir]
 EOF
-        exit 1
+        exit 0
 }
 
 if test $# -le 0; then usage; fi