variables: fixed parsing of function parameters containing undefined variables

Fixed parsing of e.g.:
${f🅰️${var1}:${var2}}

If var1 wasn't defined it was incorrectly parsed as:
f🅰️${var1

I.e. it resulted in invalid number of parameters error, as the
called function was missing the second parameter.

Now with bot variables undefined it parses as:
f🅰️${var1}:${var2}

I.e. it resulted in correct number of parameters even with
undefined variables.

Signed-off-by: Jaroslav Škarvada <jskarvad@redhat.com>

tuned/profiles/functions/functions.py

@@ -43,6 +43,6 @@ class Functions():
 	def expand(self, s):
 		if s is None:
 			return s
-		r = re.compile(r'(?<!\\)\${f:([^}]+)}')
+		r = re.compile(r'(?<!\\)\${f:(.*)}')
 		# expand functions and convert all \${f:*} to ${f:*} (unescape)
-		return re.sub(r'\\(\${f:[^}]+})', r'\1', r.sub(self.sub_func, s))
+		return re.sub(r'\\(\${f:.*})', r'\1', r.sub(self.sub_func, s))