Report some whitespace problems in buffer.
Return nil if there is no whitespace problem; otherwise, return
non-nil.
If FORCE is non-nil or C-u was pressed just
before calling `whitespace-report' interactively, it forces
`whitespace-style' to have:
empty
trailing
indentation
space-before-tab
space-after-tab
If REPORT-IF-BOGUS is non-nil, it reports only when there are any
whitespace problems in buffer.
Report if some of the following whitespace problems exist:
* If `indent-tabs-mode' is non-nil:
empty 1. empty lines at beginning of buffer.
empty 2. empty lines at end of buffer.
trailing 3. SPACEs or TABs at end of line.
indentation 4. 8 or more SPACEs at beginning of line.
space-before-tab 5. SPACEs before TAB.
space-after-tab 6. 8 or more SPACEs after TAB.
* If `indent-tabs-mode' is nil:
empty 1. empty lines at beginning of buffer.
empty 2. empty lines at end of buffer.
trailing 3. SPACEs or TABs at end of line.
indentation 4. TABS at beginning of line.
space-before-tab 5. SPACEs before TAB.
space-after-tab 6. 8 or more SPACEs after TAB.
See `whitespace-style' for documentation.
See also `whitespace-cleanup' and `whitespace-cleanup-region' for
cleaning up these problems.
(fn &optional FORCE REPORT-IF-BOGUS)