Consolidate the actual output of the formatted text into one place.
Fix a couple of edge cases:
1. If 0 is printed with a precision of 0, the printf specification says
that nothing should be output, with one exception (2b).
2. The specification for octal alternate format (%#o) adds the leading
zero not as a prefix as the 0x for hexadecimal is, but by increasing
the precision if necessary to add the zero. This means that
a. %#.2o turns 8 into "010", but 1 into "01" rather than "001".
b. %#.o prints 0 as "0" rather than "", unlike the situation for
decimal, hexadecimal and regular octal format, which all output an
empty string.
Reduce the space allocated for printing a number to the maximum actually
required (22 bytes for a 64-bit number in octal), instead of the 66
bytes previously allocated.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-15-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
6c4bcd8a46