internal/vulncheck/internal/buildinfo: remove unused field

This addresses failures on builders.

Change-Id: I065336fb6147450bf0da9740236bd6258f434528
Reviewed-on: https://go-review.googlesource.com/c/vuln/+/507275
Run-TryBot: Zvonimir Pavlinovic <zpavlinovic@google.com>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
Auto-Submit: Zvonimir Pavlinovic <zpavlinovic@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/internal/vulncheck/internal/buildinfo/buildinfo.go b/internal/vulncheck/internal/buildinfo/buildinfo.go
index f29dffa..1be795e 100644
--- a/internal/vulncheck/internal/buildinfo/buildinfo.go
+++ b/internal/vulncheck/internal/buildinfo/buildinfo.go
@@ -174,7 +174,6 @@
 
 	symbols     map[string]*macho.Symbol // Addition: symbols in the binary
 	symbolsOnce sync.Once                // Addition: for computing symbols
-	symbolsErr  error                    // Addition: error for computing symbols
 }
 
 func (x *machoExe) ReadData(addr, size uint64) ([]byte, error) {