Fix building arm EABI

  The syscall() impl on aeabi comes from syscall-eabi.S thus we do not
  need the generic syscall() impl.

  Fixes:
    AS libc/sysdeps/linux/arm/syscall-eabi.os
    CC libc/sysdeps/linux/common/syscall.os
libc/libc_so.a(syscall.os): In function `syscall':
syscall.c:(.text+0x0): multiple definition of `syscall'
libc/libc_so.a(syscall-eabi.os):(.text+0x0): first defined here

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libc/sysdeps/linux/arm/Makefile.arch

@@ -20,6 +20,7 @@ CSRC += aeabi_assert.c aeabi_atexit.c aeabi_errno_addr.c \
 	aeabi_localeconv.c aeabi_memclr.c aeabi_memcpy.c \
 	aeabi_memmove.c aeabi_memset.c find_exidx.c
 SSRC += syscall-eabi.S
+ARCH_OBJ_FILTEROUT := syscall.c
 ifeq ($(UCLIBC_HAS_WCHAR),y)
 CSRC += aeabi_mb_cur_max.c
 endif

libc/sysdeps/linux/common/Makefile.in

@@ -73,7 +73,7 @@ endif
 
 # fails for some reason
 ifneq ($(strip $(ARCH_OBJS)),)
-CSRC := $(filter-out $(notdir $(ARCH_OBJS:.o=.c)),$(CSRC))
+CSRC := $(filter-out $(notdir $(ARCH_OBJS:.o=.c)) $(ARCH_OBJ_FILTEROUT),$(CSRC))
 endif
 
 CFLAGS-ssp.c := $(SSP_DISABLE_FLAGS)