powerpc/fadump: Set core e_flags using kernel's ELF ABI version

Firmware Assisted Dump is a facility to dump kernel core with assistance
from firmware. As part of this process the kernel ELF ABI version is
stored in the core file.

Currently fadump.h defines this to 0 if it is not already defined. This
clashes with a define in elf.h which sets it based on the current task -
not based on the kernel's ELF ABI version.

Use the compiler-provided #define _CALL_ELF which tells us the ELF ABI
version of the kernel to set e_flags, this matches what binutils does.

Remove the definition in fadump.h, which becomes unused.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/fadump.h

@@ -45,10 +45,6 @@
 
 #define memblock_num_regions(memblock_type)	(memblock.memblock_type.cnt)
 
-#ifndef ELF_CORE_EFLAGS
-#define ELF_CORE_EFLAGS 0
-#endif
-
 /* Firmware provided dump sections */
 #define FADUMP_CPU_STATE_DATA	0x0001
 #define FADUMP_HPTE_REGION	0x0002

arch/powerpc/kernel/fadump.c

@@ -778,7 +778,11 @@ static int fadump_init_elfcore_header(char *bufp)
 	elf->e_entry = 0;
 	elf->e_phoff = sizeof(struct elfhdr);
 	elf->e_shoff = 0;
-	elf->e_flags = ELF_CORE_EFLAGS;
+#if defined(_CALL_ELF)
+	elf->e_flags = _CALL_ELF;
+#else
+	elf->e_flags = 0;
+#endif
 	elf->e_ehsize = sizeof(struct elfhdr);
 	elf->e_phentsize = sizeof(struct elf_phdr);
 	elf->e_phnum = 0;