aircrack-ng: add fcommon

Fixes compilation with GCC10+.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

net/aircrack-ng/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=aircrack-ng
 PKG_VERSION:=1.6
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 PKG_LICENSE:=GPL-2.0-or-later
 PKG_LICENSE_FILES:=LICENSE
 PKG_CPE_ID:=cpe:/a:aircrack-ng:aircrack-ng
@@ -90,7 +90,7 @@ CONFIGURE_ARGS += \
 	$(if $(CONFIG_AIRCRACK_NG_HWLOC),--enable-hwloc,--disable-hwloc) \
 	$(if $(CONFIG_AIRCRACK_NG_SQLITE3),--with-sqlite3=$(STAGING_DIR)/usr,--without-sqlite3)
 
-TARGET_CFLAGS += -Wall -Wextra -ffunction-sections -fdata-sections
+TARGET_CFLAGS += -Wall -Wextra -ffunction-sections -fdata-sections -fcommon
 
 ifeq ($(CONFIG_AIRCRACK_NG_OPTIMIZE_SPEED),y)
 	TARGET_CFLAGS := $(filter-out -O%,$(TARGET_CFLAGS)) -O3