drm/amdgpu: Fix style issues in amdgpu_debugfs.c

Fixes the following to align to linux coding style:

WARNING: Missing a blank line after declarations
WARNING: sizeof *rd should be sizeof(*rd)

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Praful Swarnakar <Praful.Swarnakar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c

@@ -375,7 +375,7 @@ static int amdgpu_debugfs_gprwave_open(struct inode *inode, struct file *file)
 {
 	struct amdgpu_debugfs_gprwave_data *rd;
 
-	rd = kzalloc(sizeof *rd, GFP_KERNEL);
+	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
 	if (!rd)
 		return -ENOMEM;
 	rd->adev = file_inode(file)->i_private;
@@ -388,6 +388,7 @@ static int amdgpu_debugfs_gprwave_open(struct inode *inode, struct file *file)
 static int amdgpu_debugfs_gprwave_release(struct inode *inode, struct file *file)
 {
 	struct amdgpu_debugfs_gprwave_data *rd = file->private_data;
+
 	mutex_destroy(&rd->lock);
 	kfree(file->private_data);
 	return 0;