cmd/link: fix minor bug in trampoline insertion

Fix a minor bug where it should use Textp2 instead of Textp. This
doesn't affect correctness. It just made the pre-allocation less
effective.

Change-Id: Ib3fa8ab3c64037e3582933970d051f278286353b
Reviewed-on: https://go-review.googlesource.com/c/go/+/232837
Run-TryBot: Cherry Zhang <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>
Reviewed-by: Jeremy Faller <[email protected]>

Author: cherrymui

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

@@ -2177,7 +2177,7 @@ func (ctxt *Link) textaddress() {
 
 	// merge tramps into Textp, keeping Textp in address order
 	if ntramps != 0 {
-		newtextp := make([]loader.Sym, 0, len(ctxt.Textp)+ntramps)
+		newtextp := make([]loader.Sym, 0, len(ctxt.Textp2)+ntramps)
 		i := 0
 		for _, s := range ctxt.Textp2 {
 			for ; i < ntramps && ldr.SymValue(ctxt.tramps[i]) < ldr.SymValue(s); i++ {