Improve formatting of function types.

The function type detection in r181438 and r181764 detected function
types too eagerly. This led to inconsistent formatting of inline
assembly and (together with r181687) to an incorrect formatting of calls
in macros.

Before: #define DEREF_AND_CALL_F(parameter) f (*parameter)
After:  #define DEREF_AND_CALL_F(parameter) f(*parameter)