kvx gcc-4.5 build fixes

More missing struct initialisers, for expressionS vars that in this
case don't need to be initialised.  Also an error: redefinition of
typedef 'symbolS'.  OK, so don't use a typedef.

include/opcode/kvx.h

@@ -140,13 +140,13 @@ struct kvx_pseudo_relocs
   struct kvx_reloc *kreloc;
 };
 
-typedef struct symbol symbolS;
+struct symbol;
 
 struct pseudo_func
 {
   const char *name;
 
-  symbolS *sym;
+  struct symbol *sym;
   struct kvx_pseudo_relocs pseudo_relocs;
 };