cmd/go/internal/modget: remove duplicate exit

base.ExitIfErrors() has been deferred at the begin of the function,
no need to call it again.

Change-Id: I4fc81572cfce0f84832448da667c65bb477dea22
GitHub-Last-Rev: cc156358755d516a9c8a6989f4601345bd3b55bc
GitHub-Pull-Request: golang/go#66392
Reviewed-on: https://go-review.googlesource.com/c/go/+/572576
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Sam Thanawalla <samthanawalla@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
diff --git a/src/cmd/go/internal/modget/get.go b/src/cmd/go/internal/modget/get.go
index d9f0c6a..c77321e 100644
--- a/src/cmd/go/internal/modget/get.go
+++ b/src/cmd/go/internal/modget/get.go
@@ -1673,7 +1673,6 @@
 			base.Error(err)
 		}
 	}
-	base.ExitIfErrors()
 }
 
 // reportChanges logs version changes to os.Stderr.