staging: hp100: Add space around operator +

Add space around operator + to improve code readability.
Reported by checkpatch.pl
Signed-off-by: Soumyajit Deb <debsoumyajit100@gmail.com>
Link: https://lore.kernel.org/r/20200323054836.48816-2-debsoumyajit100@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/hp/hp100.c

@@ -119,7 +119,7 @@
 #define HP100_REGION_SIZE	0x20	/* for ioports */
 #define HP100_SIG_LEN		8	/* same as EISA_SIG_LEN */
 
-#define HP100_MAX_PACKET_SIZE	(1536+4)
+#define HP100_MAX_PACKET_SIZE	(1536 + 4)
 #define HP100_MIN_PACKET_SIZE	60
 
 #ifndef HP100_DEFAULT_RX_RATIO