vo_opengl: do not blindly reject all Microsoft's OpenGL implementations

This change enables mpv to work in the WSL2 (WSLg) environment where
OpenGL is implemented on top of D3D12.

This reverts commit 149d98d.

Mentioned OpenGL implementation (GDI Generic) in the original change
will be rejected by version check, so there is no need to handle it
manually.

Signed-off-by: Kacper Michajłow <kasper93@gmail.com>

video/out/opengl/common.c

@@ -37,12 +37,12 @@
 static bool is_software_gl(GL *gl)
 {
     const char *renderer = gl->GetString(GL_RENDERER);
-    const char *vendor = gl->GetString(GL_VENDOR);
-    return !(renderer && vendor) ||
+    // Note we don't attempt to blacklist Microsoft's fallback implementation.
+    // It only provides OpenGL 1.1 and will be skipped anyway.
+    return !renderer ||
            strcmp(renderer, "Software Rasterizer") == 0 ||
            strstr(renderer, "llvmpipe") ||
            strstr(renderer, "softpipe") ||
-           strcmp(vendor, "Microsoft Corporation") == 0 ||
            strcmp(renderer, "Mesa X11") == 0 ||
            strcmp(renderer, "Apple Software Renderer") == 0;
 }