Core: Remove some unused variables

pcsx2/CDVD/CDVD.cpp

@@ -502,7 +502,6 @@ s32 cdvdReadSubQ(s32 lsn, cdvdSubQ* subq)
 
 static void cdvdDetectDisk()
 {
-	wxString str;
 	cdvd.Type = DoCDVDdetectDiskType();
 	cdvdReloadElfInfo();
 }

pcsx2/DebugTools/DisR5900asm.cpp

@@ -607,9 +607,6 @@ void (*COP2SPECIAL2PrintTable[128])( string& output ) =
 
 void disR5900Fasm( string& output, u32 code, u32 pc )
 {
-	string dbuf;
-	char obuf[48];
-
 	opcode_addr = pc;
 	disasmOpcode = code;