xdrgen: Address some checkpatch whitespace complaints

This is a roll-up of three template fixes that eliminate noise from
checkpatch output so that it's easier to spot non-trivial problems.

To follow conventional kernel C style, when a union declaration is
marked with "pragma public", there should be a blank line between
the emitted "union xxx { ... };" and the decoder and encoder
function declarations.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

tools/net/sunrpc/xdrgen/templates/C/enum/declaration/enum.j2

@@ -1,4 +1,3 @@
 {# SPDX-License-Identifier: GPL-2.0 #}
-
 bool xdrgen_decode_{{ name }}(struct xdr_stream *xdr, {{ name }} *ptr);
 bool xdrgen_encode_{{ name }}(struct xdr_stream *xdr, {{ name }} value);

tools/net/sunrpc/xdrgen/templates/C/enum/definition/close.j2

@@ -1,3 +1,4 @@
 {# SPDX-License-Identifier: GPL-2.0 #}
 };
+
 typedef enum {{ name }} {{ name }};

tools/net/sunrpc/xdrgen/templates/C/enum/definition/close_be.j2

@@ -1,3 +1,4 @@
 {# SPDX-License-Identifier: GPL-2.0 #}
 };
+
 typedef __be32 {{ name }};

tools/net/sunrpc/xdrgen/templates/C/union/definition/close.j2

@@ -3,6 +3,7 @@
 };
 {%- if name in public_apis %}
 
+
 bool xdrgen_decode_{{ name }}(struct xdr_stream *xdr, struct {{ name }} *ptr);
 bool xdrgen_encode_{{ name }}(struct xdr_stream *xdr, const struct {{ name }} *ptr);
 {%- endif -%}