amdgpu_plugin: fix lint error

$ make lint
 ...
 # Do not append \n to pr_perror, pr_pwarn or fail
 ! git --no-pager grep -E '^\s*\<(pr_perror|pr_pwarn|fail)\>.*\\n"'
 plugins/amdgpu/amdgpu_plugin.c:		pr_perror("%s(), Can't handle VMAs of input device\n", __func__);
 make: *** [Makefile:470: lint] Error 1

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

plugins/amdgpu/amdgpu_plugin.c

@@ -412,7 +412,7 @@ int amdgpu_plugin_handle_device_vma(int fd, const struct stat *st_buf)
 	/* Determine if input is a DRM device and therefore is supported */
 	ret = amdgpu_plugin_drm_handle_device_vma(fd, st_buf);
 	if (ret)
-		pr_perror("%s(), Can't handle VMAs of input device\n", __func__);
+		pr_perror("%s(), Can't handle VMAs of input device", __func__);
 
 	return ret;
 }