perf beauty socket: Prep to receive more input header files

Move from ternary like expression to an if block, this way we'll
have just the extra lines for new files in the following patches.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/trace/beauty/socket.sh

 #!/bin/sh
 # SPDX-License-Identifier: LGPL-2.1
 
-[ $# -eq 1 ] && uapi_header_dir=$1 || uapi_header_dir=tools/include/uapi/linux/
+if [ $# -gt 0 ] ; then
+	uapi_header_dir=$1
+else
+	uapi_header_dir=tools/include/uapi/linux/
+fi
 
 printf "static const char *socket_ipproto[] = {\n"
 regex='^[[:space:]]+IPPROTO_(\w+)[[:space:]]+=[[:space:]]+([[:digit:]]+),.*'