Program: Make LinkResult use gl::ErrorOrResult.

This simplifies the error handling code, and allows the use of the
ANGLE_TRY macro (and friends).

BUG=angleproject:1576

Change-Id: I3142388b10d0dd67a7f49a5c8c3d11102996be93
Reviewed-on: https://chromium-review.googlesource.com/411201
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/ProgramVk.cpp b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
index 591cf06..a83f826 100644
--- a/src/libANGLE/renderer/vulkan/ProgramVk.cpp
+++ b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
@@ -25,7 +25,7 @@
 LinkResult ProgramVk::load(gl::InfoLog &infoLog, gl::BinaryInputStream *stream)
 {
     UNIMPLEMENTED();
-    return LinkResult(false, gl::Error(GL_INVALID_OPERATION));
+    return gl::Error(GL_INVALID_OPERATION);
 }
 
 gl::Error ProgramVk::save(gl::BinaryOutputStream *stream)
@@ -42,7 +42,7 @@
 LinkResult ProgramVk::link(const gl::ContextState &data, gl::InfoLog &infoLog)
 {
     UNIMPLEMENTED();
-    return LinkResult(false, gl::Error(GL_INVALID_OPERATION));
+    return gl::Error(GL_INVALID_OPERATION);
 }
 
 GLboolean ProgramVk::validate(const gl::Caps &caps, gl::InfoLog *infoLog)