Make AI profile tables actually stop parsing if #End is missing.

By making parse_ai_profiles_tbl() actually check the return value of skip_to_start_of_string_either() (and break if the appropriate characters aren't found), AI profile tables should no longer keep parsing past the end of the file and into invalid memory, until they either find an "#End" in memory somewhere or just plain crash.

As a pleasant bonus, a missing "#End" should now generate an appropriate error message.

Author: MageKing17

code/ai/ai_profiles.cpp

@@ -498,7 +498,8 @@ void parse_ai_profiles_tbl(const char *filename)
 				}
 
 				// find next valid option
-				skip_to_start_of_string_either("$", "#");
+				if (!skip_to_start_of_string_either("$", "#"))
+					break;
 				saved_Mp = Mp;
 			}
 		}