Fix test operators

`test` does not support `==`, but deceptively returns `true` in case you use it.

Author: djurny

config/bootscripts/boot-generic.cmd.template

@@ -124,15 +124,15 @@ if test "${docker_optimizations}" = "on" ; then
 	setenv bootargs "${bootargs} cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory"
 fi
 
-if test "${vendor}" == "allwinner" ; then
+if test "${vendor}" = "allwinner" ; then
 	if test "${disp_mem_reserves}" = "off" ; then
 		setenv bootargs "${bootargs} sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_fb_mem_reserve=16"
 	fi
 fi
-if test "${vendor}" == "marvell" ; then
+if test "${vendor}" = "marvell" ; then
 	#
 fi
-if test "${vendor}" == "rockchip" ; then
+if test "${vendor}" = "rockchip" ; then
 	#
 fi