buildsys: fix detection of silent make
buildsys: fix detection of silent make

The MAKEFLAGS variable contains all the flags without the leading dash.
From the GNU make manual:
	This variable is set up automatically by make to contain the flag
	letters that make received. Thus, if you do ‘make -ks’ then MAKEFLAGS
	gets the value ‘ks’.

Signed-off-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>

brgl/uclibc-ng,ndmsystems/uClibc,hwoarang/uClibc,skristiansson/uClibc-or1k,groundwater/uClibc,hjl-tools/uClibc,kraj/uclibc-ng,ddcc/klee-uclibc-0.9.33.2,hjl-tools/uClibc,brgl/uclibc-ng,wbx-github/uclibc-ng,ndmsystems/uClibc,ddcc/klee-uclibc-0.9.33.2,foss-xtensa/uClibc,skristiansson/uClibc-or1k,hwoarang/uClibc,waweber/uclibc-clang,kraj/uClibc,czankel/xtensa-uclibc,ndmsystems/uClibc,ffainelli/uClibc,wbx-github/uclibc-ng,groundwater/uClibc,groundwater/uClibc,groundwater/uClibc,czankel/xtensa-uclibc,kraj/uClibc,waweber/uclibc-clang,atgreen/uClibc-moxie,ffainelli/uClibc,czankel/xtensa-uclibc,ddcc/klee-uclibc-0.9.33.2,wbx-github/uclibc-ng,ddcc/klee-uclibc-0.9.33.2,brgl/uclibc-ng,waweber/uclibc-clang,ndmsystems/uClibc,majek/uclibc-vx32,atgreen/uClibc-moxie,ffainelli/uClibc,hjl-tools/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,majek/uclibc-vx32,wbx-github/uclibc-ng,hwoarang/uClibc,mephi42/uClibc,mephi42/uClibc,hjl-tools/uClibc,skristiansson/uClibc-or1k,foss-for-synopsys-dwc-arc-processors/uClibc,skristiansson/uClibc-or1k,majek/uclibc-vx32,mephi42/uClibc,atgreen/uClibc-moxie,majek/uclibc-vx32,hjl-tools/uClibc,foss-xtensa/uClibc,foss-xtensa/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,kraj/uClibc,ffainelli/uClibc,atgreen/uClibc-moxie,foss-for-synopsys-dwc-arc-processors/uClibc,groundwater/uClibc,waweber/uclibc-clang,brgl/uclibc-ng,czankel/xtensa-uclibc,foss-xtensa/uClibc,kraj/uclibc-ng,kraj/uClibc,ffainelli/uClibc,kraj/uclibc-ng,mephi42/uClibc,hwoarang/uClibc,kraj/uclibc-ng