package/ascii-invaders: drop the SOURCE variable

There is no need to override the SOURCE variable when the github macro
is used, and in fact keeping the default SOURCE value gives a much
more sensible tarball name, so let's drop the SOURCE variable
entirely.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/ascii-invaders/ascii-invaders.hash

@@ -1,5 +1,5 @@
 # Locally calculated
-sha512	326708ffc2c277e04575920c58f6a267e0bf46f8d2a3dbca9b5c317fb01006d4f673ab35f92f292549cc52dbee4400a84c85478eb81b9bd7703689a705547bc7	1.0.1.tar.gz
+sha512	326708ffc2c277e04575920c58f6a267e0bf46f8d2a3dbca9b5c317fb01006d4f673ab35f92f292549cc52dbee4400a84c85478eb81b9bd7703689a705547bc7	ascii-invaders-1.0.1.tar.gz
 
 # Hash for license file
 sha512	1e455684996d7733b2f1ccd4606d034694d16ceff6ede6125d7f1537d20dabe05976cca4cef5cbf6c31352cbd62a515fd8e34a2ffb54dae1181c1116b24c6cf7	LICENSE

package/ascii-invaders/ascii-invaders.mk

@@ -5,7 +5,6 @@
 ################################################################################
 
 ASCII_INVADERS_VERSION = 1.0.1
-ASCII_INVADERS_SOURCE = $(ASCII_INVADERS_VERSION).tar.gz
 ASCII_INVADERS_SITE = $(call github,macdice,ascii-invaders,v$(ASCII_INVADERS_VERSION))
 ASCII_INVADERS_DEPENDENCIES = ncurses
 ASCII_INVADERS_LICENSE = GPL-2.0+