Remove trivial warnings.
correct format strings
Remove unused functions

(actually #if 0 // unused function them out)
strcpy->strlcpy
strcat -> strlcat
all warnings removed from zvol. This requires testing as some of the
warnings were non-trivial.
Correct calling convention preserve constness.
Correct dprintf macro. Correct incorrect .h file function definition.
Maintain C99 style for variable declarations, and conditionally compile linux variables out.
Merge remote-tracking branch 'origin/warnings'