shrc: Use mkdir -v alias only when using coreutils

shrc

@@ -278,7 +278,7 @@ alias cp="cp -v"
 alias mv="mv -v"
 alias rm="rm -v"
 alias mkdir="mkdir -v"
-alias rmdir="rmdir -v"
+$gnu_coreutils && alias rmdir="rmdir -v"
 alias psaux="ps auxww"
 alias modest="ionice -c 2 -n 7 nice -n 19"
 alias e=exec