buildsys: check LDFLAGS through driver
buildsys: check LDFLAGS through driver

We run the linker through the compiler-driver, so we have to check
linker flags through the driver, too.
Otherwise we might check $LD's flags while we will run $CC's linker
and those might be different beasts.

Signed-off-by: Bernhard Reutner-Fischer <ce1ac9e9ad16abccd7821f371ad381197b4768ac@gmail.com>

kraj/uClibc,kraj/uclibc-ng,groundwater/uClibc,hjl-tools/uClibc,kraj/uClibc,hjl-tools/uClibc,kraj/uclibc-ng,ffainelli/uClibc,hjl-tools/uClibc,groundwater/uClibc,ffainelli/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,majek/uclibc-vx32,brgl/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,groundwater/uClibc,wbx-github/uclibc-ng,wbx-github/uclibc-ng,wbx-github/uclibc-ng,wbx-github/uclibc-ng,brgl/uclibc-ng,groundwater/uClibc,hjl-tools/uClibc,ffainelli/uClibc,kraj/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,ffainelli/uClibc,kraj/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,ffainelli/uClibc,brgl/uclibc-ng,kraj/uclibc-ng,majek/uclibc-vx32,brgl/uclibc-ng,kraj/uclibc-ng,hjl-tools/uClibc,majek/uclibc-vx32,groundwater/uClibc,majek/uclibc-vx32