SCI32: Remove backslashes from PQ:SWAT extra save game files

The original interpreter created subdirectories for each in-game
profile, but copying this behaviour would add a lot of
superfluous complexity to the save game system in ScummVM, and
may not be portable to all supported platforms. Instead, when the
game tries to save its files to a subdirectory, the backslash in
the file name is replaced with an underscore so it can be created
successfully on filesystems where backslash is an illegal file
name character.

This has a side-effect of causing all save games to be displayed
under all profiles, instead of just the ones "belonging" to a
particular profile, but this seems like a reasonable trade-off
given that there is no reason to play this game with more than one
profile.

engines/sci/engine/kfile.cpp

@@ -427,6 +427,13 @@ reg_t kFileIOOpen(EngineState *s, int argc, reg_t *argv) {
 				return make_reg(0, handle);
 			}
 		}
+	} else if (g_sci->getGameId() == GID_PQSWAT) {
+		// PQSWAT tries to create subdirectories for each game profile
+		for (Common::String::iterator it = name.begin(); it != name.end(); ++it) {
+			if (*it == '\\') {
+				*it = '_';
+			}
+		}
 	}
 
 	// See kMakeSaveCatName