Fix GNU make v3.80 compatibility

Commits 1f6601a and 094d82d introduced the "else ifeq" construct, which
requires GNU make v3.81 or higher.  This breaks the build on RHEL4 hosts.

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

libc/sysdeps/linux/common/Makefile.in

@@ -42,9 +42,11 @@ ifeq ($(UCLIBC_HAS_THREADS_NATIVE),y)
 CSRC := $(filter-out fork.c getpid.c raise.c open.c close.c read.c write.c, $(CSRC))
 ifeq ($(TARGET_ARCH),arm)
 CSRC := $(filter-out vfork.c, $(CSRC))
-else ifeq ($(TARGET_ARCH),x86_64)
+else
+ifeq ($(TARGET_ARCH),x86_64)
 CSRC := $(filter-out vfork.c, $(CSRC))
-else ifeq ($(TARGET_ARCH),mips)
+else
+ifeq ($(TARGET_ARCH),mips)
 ifeq ($(CONFIG_MIPS_O32_ABI),y)
 CSRC := $(filter-out waitpid.c, $(CSRC))
 endif
@@ -52,6 +54,8 @@ else
 CSRC := $(filter-out waitpid.c, $(CSRC))
 endif
 endif
+endif
+endif
 
 ifneq ($(ARCH_USE_MMU),y)
 # stubbed out in mman.h