Fix parsing of GNU which output

The GNU version of which outputs error messages as follows:

 $ which aaaaaa
 which: no aaaaaa in ...

Note that the error message that starts with "no" is preceded by
"which: ".

Author: joncave

lib/misc/file

@@ -110,7 +110,7 @@ file_show_real_filename () {
 		*)
 			# AIX errors to stdout, ideally we'd use $? but which on Solaris doesn't exit() differently depending on result :(
 			# TODO maybe we should break it out with uname checks?
-			realfilename="`which \"\`basename \\\"${pattern}\\\"\`\" 2>&1 | egrep -v \"There is no |^no \"`"
+			realfilename="`which \"\`basename \\\"${pattern}\\\"\`\" 2>&1 | egrep -v \"There is no |^(which: )?no \"`"
 			if [ -n "${realfilename}" ]
 			then
 				printf -- "${realfilename}\n"