ardupilotwaf: fix spec args as distcc doesn't like it

Tools/ardupilotwaf/boards.py

@@ -598,7 +598,7 @@ class chibios(Board):
             '-mno-thumb-interwork',
             '-mthumb',
             '--specs=nano.specs',
-            '-specs=nosys.specs',
+            '--specs=nosys.specs',
             '-DCHIBIOS_BOARD_NAME="%s"' % self.name,
             '-D__USE_CMSIS',
             '-Werror=deprecated-declarations'
@@ -641,8 +641,8 @@ class chibios(Board):
             '-nostartfiles',
             '-mno-thumb-interwork',
             '-mthumb',
-            '-specs=nano.specs',
-            '-specs=nosys.specs',
+            '--specs=nano.specs',
+            '--specs=nosys.specs',
             '-L%s' % env.BUILDROOT,
             '-L%s' % cfg.srcnode.make_node('modules/ChibiOS/os/common/startup/ARMCMx/compilers/GCC/ld/').abspath(),
             '-L%s' % cfg.srcnode.make_node('libraries/AP_HAL_ChibiOS/hwdef/common/').abspath(),