Fix SPIR-V emptiness condition in fuzzer

Fixes a problem where the fuzzer was ignoring non-empty SPIR-V
binaries.

Fixes: tint:1004
Change-Id: I9fa98764b7408dbd53d5b56424805e2fa331a118
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58385
Auto-Submit: Alastair Donaldson <afdx@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/fuzzers/tint_common_fuzzer.cc b/fuzzers/tint_common_fuzzer.cc
index 97bdcc7..4c427f1 100644
--- a/fuzzers/tint_common_fuzzer.cc
+++ b/fuzzers/tint_common_fuzzer.cc
@@ -202,7 +202,7 @@
 #endif  // TINT_BUILD_WGSL_READER
 #if TINT_BUILD_SPV_READER
     case InputFormat::kSpv: {
-      if (spirv_input.empty()) {
+      if (!spirv_input.empty()) {
         program = reader::spirv::Parse(spirv_input);
       }
       break;