libc/uClibc: fix building on system with recent glibc

While trying to build a toolchain with ct-ng 1.5.0,
arm-unknown-linux-uclibcgnueabi target,
I get the following error:

[INFO ] Installing C library headers
[EXTRA] Copying sources to build dir
[EXTRA] Applying configuration
[EXTRA] Building headers
[EXTRA] Installing headers
[ERROR] extra/scripts/unifdef.c:209: error: conflicting types for 'getline'
[ERROR] make[2]: *** [extra/scripts/unifdef] Error 1
[ERROR] Build failed in step 'Installing C library headers'

The following patch solves the problem.
(It's a backport of this uClibc commit:
http://git.uclibc.org/uClibc/commit/?id=49e81cada73616864b9b31df0aeb6961c30f5a6e
)

[--SNIP from another mail--]
AFAIK this is a problem since glibc 2.10.
(transplanted from 1ba79f2126df8bd89120899a58f2d0bcc2e9c771)

--- libc/nptl/sysdeps/unix/sysv/linux/alpha/sysdep-cancel.h    2006/10/29 21:48:06     1.6

+++ libc/nptl/sysdeps/unix/sysv/linux/alpha/sysdep-cancel.h    2007/03/13 21:28:03     1.7

@@ -55,6 +55,7 @@

 	bne	a3, SYSCALL_ERROR_LABEL;			\

 __LABEL($pseudo_ret)						\

 	.subsection 2;						\

+	cfi_startproc;						\

 __LABEL($pseudo_cancel)						\

 	subq	sp, 64, sp;					\

 	cfi_def_cfa_offset(64);					\

@@ -90,12 +91,13 @@

 	cfi_def_cfa_offset(0);					\

 __LABEL($syscall_error)						\

 	SYSCALL_ERROR_HANDLER;					\

+	cfi_endproc;						\

 	.previous

 # undef PSEUDO_END

 # define PSEUDO_END(sym)					\

-	.subsection 2;						\

 	cfi_endproc;						\

+	.subsection 2;						\

 	.size sym, .-sym

 # define SAVE_ARGS_0	/* Nothing.  */