Also quote the quoted string characters.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20928 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/tools/fs_shell/fs_shell_command.cpp

@@ -35,7 +35,7 @@ prepare_command_string(const char *const *argv, int argc, char *buffer,
 			add_char(buffer, bufferSize, ' ');
 
 		while (*arg) {
-			if (strchr(" \\", *arg))
+			if (strchr(" \"'\\", *arg))
 				add_char(buffer, bufferSize, '\\');
 			add_char(buffer, bufferSize, *arg);
 			arg++;