Invoke aout N_* macros with pointer to struct internal_exec

No functional changes here.

BTW, some of these headers don't seem to be used anywhere:
include/aout/dynix3.h, include/aout/encap.h, include/aout/hp.h,
gas/config/aout_gnu.h

bfd/
	* aout-adobe.c: Invoke aout N_* macros with pointer to
	struct internal_exec.
	* aout-arm.c: Likewise.
	* aout-cris.c: Likewise.
	* aout-target.h: Likewise.
	* aout-tic30.c: Likewise.
	* aoutf1.h: Likewise.
	* aoutx.h: Likewise.
	* bout.c: Likewise.
	* freebsd.h: Likewise.
	* gen-aout.c: Likewise.
	* hp300hpux.c: Likewise.
	* i386aout.c: Likewise.
	* i386linux.c: Likewise.
	* i386lynx.c: Likewise.
	* i386mach3.c: Likewise.
	* i386os9k.c: Likewise.
	* libaout.h: Likewise.
	* m68klinux.c: Likewise.
	* m88kmach3.c: Likewise.
	* mipsbsd.c: Likewise.
	* netbsd.h: Likewise.
	* pc532-mach.c: Likewise.
	* pdp11.c: Likewise.
	* riscix.c: Likewise.
	* sparclinux.c: Likewise.
	* sparclynx.c: Likewise.
gas/
	* config/aout_gnu.h: Invoke aout N_* macros with pointer to
	struct internal_exec.
include/
	* bout.h: Invoke aout N_* macros with pointer to
	struct internal_exec.
	* os9k.h: Likewise.
include/aout/
	* adobe.h: Invoke aout N_* macros with pointer to
	struct internal_exec.
	* aout64.h: Likewise.
	* dynix3.h: Likewise.
	* encap.h: Likewise.
	* hp.h: Likewise.
	* hp300hpux.h: Likewise.
	* sun4.h: Likewise.

bfd/i386linux.c

@@ -70,11 +70,11 @@ i386linux_write_object_contents (bfd *abfd)
   struct external_exec exec_bytes;
   struct internal_exec *execp = exec_hdr (abfd);
 
-  N_SET_MACHTYPE (*execp, M_386);
+  N_SET_MACHTYPE (execp, M_386);
 
   obj_reloc_entry_size (abfd) = RELOC_STD_SIZE;
 
-  WRITE_HEADERS(abfd, execp);
+  WRITE_HEADERS (abfd, execp);
 
   return TRUE;
 }