saves: Remove noop allocation/deallocation

Compilers (at least gcc 10) were already reaching that conclusion, so
this shouldn’t change code generation at all.

This piece of code got introduced in commit
3eb9de4614 when upgrading to save state
version 1 (we’re at version 12), and commit
64073a2558 added some OOP on top of it so
that cp15 was in charge of handling that memory.  The code never got
cleaned until now.

desmume/src/saves.cpp

@@ -624,17 +624,8 @@ static bool cp15_loadstate(EMUFILE &is, int size)
 	if (version == 0)
 	{
 		//ARM7 not have coprocessor
-		
-		// TODO: What's going on here with tmp_buf?
-		u8 *tmp_buf = new u8 [sizeof(armcp15_t)];
-		if (!tmp_buf) return false;
-		
 		if (!cp15.loadone(is))
-		{
-			delete [] tmp_buf;
 			return false;
-		}
-		delete [] tmp_buf;
 	}
 
 	return true;