5l: fix set but not used warnings

R=rsc, iant
CC=golang-dev
https://golang.org/cl/4538083

src/cmd/5l/asm.c

@@ -295,15 +295,12 @@ asmb(void)
 {
 	int32 t;
 	int a, dynsym;
-	uint32 va, fo, w, symo, startva, elfsymo, elfstro, elfsymsize;
-	int strtabsize;
+	uint32 fo, symo, startva, elfsymo, elfstro, elfsymsize;
 	ElfEhdr *eh;
 	ElfPhdr *ph, *pph;
 	ElfShdr *sh;
 	Section *sect;
 
-	strtabsize = 0;
-
 	if(debug['v'])
 		Bprint(&bso, "%5.2f asmb\n", cputime());
 	Bflush(&bso);
@@ -467,9 +464,7 @@ asmb(void)
 		/* elf arm */
 		eh = getElfEhdr();
 		fo = HEADR;
-		va = INITTEXT;
 		startva = INITTEXT - fo;	/* va of byte 0 of file */
-		w = textsize;
 		
 		/* This null SHdr must appear before all others */
 		sh = newElfShdr(elfstr[ElfStrEmpty]);

src/cmd/5l/obj.c

@@ -412,7 +412,7 @@ ldobj1(Biobuf *f, char *pkg, int64 len, char *pn)
 {
 	int32 ipc;
 	Prog *p;
-	Sym *h[NSYM], *s, *di;
+	Sym *h[NSYM], *s;
 	int v, o, r, skip;
 	uint32 sig;
 	char *name;
@@ -424,7 +424,6 @@ ldobj1(Biobuf *f, char *pkg, int64 len, char *pn)
 	lastp = nil;
 	ntext = 0;
 	eof = Boffset(f) + len;
-	di = S;
 	src[0] = 0;
 
 newloop:

src/cmd/5l/span.c

@@ -168,7 +168,6 @@ span(void)
 	Optab *o;
 	int m, bflag, i, v;
 	int32 c, otxt, out[6];
-	int lastthumb = -1;
 	Section *sect;
 	uchar *bp;
 
@@ -187,7 +186,6 @@ span(void)
 		p->pc = c;
 		cursym->value = c;
 
-		lastthumb = thumb;
 		autosize = p->to.offset + 4;
 		if(p->from.sym != S)
 			p->from.sym->value = c;