internal/lsp/cache: fix nil check by adding missing "continue"

Without this accessing gof.ast.file.Pos() will panic if gof.ast.file is nil

Change-Id: I829f3667d201f026fcf0475f4fdabce0aced58f8

Change-Id: I829f3667d201f026fcf0475f4fdabce0aced58f8
GitHub-Last-Rev: 777c015d691bf0d14cab5bb0bca6749cc9bdf605
GitHub-Pull-Request: golang/tools#119
Reviewed-on: https://go-review.googlesource.com/c/tools/+/182420
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/internal/lsp/cache/check.go b/internal/lsp/cache/check.go
index 38b3632..32bd381 100644
--- a/internal/lsp/cache/check.go
+++ b/internal/lsp/cache/check.go
@@ -178,6 +178,7 @@
 		}
 		if gof.ast.file == nil {
 			imp.view.session.log.Errorf(ctx, "no AST for %s", filename)
+			continue
 		}
 		pos := gof.ast.file.Pos()
 		if !pos.IsValid() {