Cleanup kldxref sources

[mhorne063_gmail.com]

Summary

There are some style inconsistencies in the kldxref source files, this patch should fix most of them in accordance to style(9)
Some of these were discussed on a previous revision here.
Quick summary:

• Use designated initializers for structs
• Always use bracketed return style
• No initialization in declarations
• Align function prototype names
• Remove old commented code/unused imports

[mhorne063_gmail.com]

usr.sbin/kldxref/ef.c

121

The alignment here is correct, phabricator just doesn't seem to display it properly.

usr.sbin/kldxref/ef_obj.c

139

Same as above, alignment doesn't display properly in phabricator.

[kib]

usr.sbin/kldxref/ef.c

83

Can you extract the change of the return value to Elf_Off ?

297

Perhaps use %jx and (uintmax_t)ef_get_offset().

304

if (error != 0)

[mhorne063_gmail.com]

Use explicit conditions (error != 0).
Remove the change to ef_get_offset() return type for another patch.

[mhorne063_gmail.com]

Changed pointer justification in the struct at the beginning of ef.c