kgdb,i386: use address that SP register points to in the exception frame

The treatment of the SP register is different on x86_64 and i386.
This is a regression fix that lived outside the mainline kernel from
2.6.27 to now.  The regression was a result of the original merge
consolidation of the i386 and x86_64 archs to x86.

The incorrectly reported SP on i386 prevented stack tracebacks from
working correctly in gdb.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

arch/x86/kernel/kgdb.c

@@ -88,6 +88,7 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
 	gdb_regs[GDB_SS]	= __KERNEL_DS;
 	gdb_regs[GDB_FS]	= 0xFFFF;
 	gdb_regs[GDB_GS]	= 0xFFFF;
+	gdb_regs[GDB_SP]	= (int)&regs->sp;
 #else
 	gdb_regs[GDB_R8]	= regs->r8;
 	gdb_regs[GDB_R9]	= regs->r9;
@@ -100,8 +101,8 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
 	gdb_regs32[GDB_PS]	= regs->flags;
 	gdb_regs32[GDB_CS]	= regs->cs;
 	gdb_regs32[GDB_SS]	= regs->ss;
-#endif
 	gdb_regs[GDB_SP]	= regs->sp;
+#endif
 }
 
 /**