mips: fix errno setting after syscall

If there was an error during syscall then after it's completion a3
register holds a non-zero value and v0 holds an actual error code which
should be saved in errno. This can be achieved by calling
__syscall_error with the value from v0 as a parameter. So this value
should be stored in a0, but the appropriate assembly instructions are
missing. Fixed this now by adding "move a0, v0".

I think it was once fixed by 58c5f8ba4cdf62342d05a546d15404cbbb3c4e07
but then something went wrong. Again...

Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libc/sysdeps/linux/mips/sysdep.h

@@ -98,7 +98,8 @@
 #ifdef __PIC__
 #define PSEUDO(name, syscall_name, args) 		\
   .align 2;						\
-  99: la t9,__syscall_error;				\
+  99: move a0, v0;					\
+  la t9,__syscall_error;				\
   jr t9;						\
   ENTRY(name)						\
   .set noreorder;					\
@@ -112,7 +113,8 @@ L(syse1):
 #define PSEUDO(name, syscall_name, args) 		\
   .set noreorder;					\
   .align 2;						\
-  99: j __syscall_error;				\
+  99: move a0, v0;					\
+  j __syscall_error;					\
   nop;							\
   ENTRY(name)						\
   .set noreorder;					\

libpthread/linuxthreads/sysdeps/unix/sysv/linux/mips/sysdep-cancel.h

@@ -28,7 +28,8 @@
 # undef PSEUDO
 # define PSEUDO(name, syscall_name, args)				      \
   .align 2;								      \
-  99: la t9,__syscall_error;						      \
+  99: move a0, v0; 							      \
+  la t9,__syscall_error;						      \
   jr t9;								      \
   ENTRY (name)								      \
     .set noreorder;							      \

libpthread/nptl/sysdeps/unix/sysv/linux/mips/sysdep-cancel.h

@@ -26,12 +26,12 @@
 
 # ifdef __PIC__
 #  define PSEUDO_CPLOAD .cpload t9;
-#  define PSEUDO_ERRJMP la t9, __syscall_error; jr t9;
+#  define PSEUDO_ERRJMP move a0, v0; la t9, __syscall_error; jr t9;
 #  define PSEUDO_SAVEGP sw gp, 32(sp); cfi_rel_offset (gp, 32);
 #  define PSEUDO_LOADGP lw gp, 32(sp);
 # else
 #  define PSEUDO_CPLOAD
-#  define PSEUDO_ERRJMP j __syscall_error;
+#  define PSEUDO_ERRJMP move a0, v0; j __syscall_error;
 #  define PSEUDO_SAVEGP
 #  define PSEUDO_LOADGP
 # endif