cmd/link: remove duplicate symtab entry for global functions

golang.org/cl/16436 added a local symbol for every global function, but also
added a duplicate entry for the global symbol. Surprisingly this hasn't caused
any noticeable problems, but it's still wrong.

Change-Id: Icd3906760f8aaf7bef31ffd4f2d866d73d36dc2c
Reviewed-on: https://go-review.googlesource.com/16581Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/link/internal/ld/symtab.go

@@ -175,6 +175,7 @@ func putelfsym(x *LSym, s string, t int, addr int64, size int64, ver int, go_ *L
 		putelfsyment(putelfstr("local."+s), addr, size, STB_LOCAL<<4|type_&0xf, elfshnum, other)
 		x.LocalElfsym = int32(numelfsym)
 		numelfsym++
+		return
 	} else if bind != elfbind {
 		return
 	}