scons: Build libOpenVG.dll & libEGL.dll

But without creating liblibOpenVG or liblibEGL elsewhere.

Thanks Chia-I Wu for pointing this out.

src/gallium/targets/egl-static/SConscript

@@ -111,8 +111,11 @@ if env['drm']:
         svga,
     ])
 
+# libEGL.dll
+env['SHLIBPREFIX'] = 'lib'
+
 egl_gallium = env.SharedLibrary(
-    target ='libEGL',
+    target ='EGL',
     source = sources,
 )
 

src/mapi/vgapi/SConscript

@@ -44,6 +44,9 @@ if env['platform'] != 'winddk':
 
 	env.Depends(vgapi_objects, vgapi_header)
 
+	# libOpenVG.dll
+	env['SHLIBPREFIX'] = 'lib'
+
 	openvg = env.SharedLibrary(
 		target = 'OpenVG',
 		source = vgapi_objects,