Avoid quiet conversion of pointer to bool

* src/location.c (caret_set_file):
* src/scan-code.l (contains_dot_or_dash):
Do not quietly convert pointer to bool, as Oracle Developer Studio
12.6 complains and it is arguably confusing style anyway.

src/location.c

@@ -257,7 +257,7 @@ caret_set_file (const char *file)
             caret_free ();
         }
     }
-  return caret_info.file;
+  return !!caret_info.file;
 }
 
 void caret_init (void)

src/scan-code.l

@@ -216,7 +216,7 @@ is_dot_or_dash (char ch)
 static inline bool
 contains_dot_or_dash (const char* p)
 {
-  return strpbrk(p, ".-");
+  return !!strpbrk (p, ".-");
 }
 
 /* Defines a variant of a symbolic name resolution. */