Fix documentation build errors

This fixes the following errors building the findutils documentation:
find.texi:53: misplaced {
find.texi:53: misplaced }
find.texi:1862: warning: node `Formatting Flags' is next for `Time Directives' in menu but not in sectioning
find.texi:1975: warning: node `Formatting Flags' is next for `Combined Time Formats' in sectioning but not in menu
find.texi:2004: warning: node prev `Formatting Flags' in menu `Time Directives' and in sectioning `Combined Time Formats' differ
find.texi:2004: warning: node up `Formatting Flags' in menu `Format Directives' and in sectioning `Time Formats' differ
find.texi:1893: node `Time Formats' lacks menu item for `Formatting Flags' despite being its Up target

Upstream-Status: Backport
Signed-off-by: Jonathan Liu <net147@gmail.com>

--- a/doc/find.texi
+++ b/doc/find.texi
@@ -50,7 +50,7 @@ Texts.  A copy of the license is included in the section entitled

 @page
 @vskip 0pt plus 1filll
-@insertcopying{}
+@insertcopying
 @end titlepage

 @contents
@@ -1665,6 +1665,7 @@ no output is ever sent to it.
 * Escapes::
 * Format Directives::
 * Time Formats::
+* Formatting Flags::
 @end menu

 @node Escapes
@@ -1733,7 +1734,6 @@ from the novel you are reading.
 * Size Directives::
 * Location Directives::
 * Time Directives::
-* Formatting Flags::
 @end menu

 @node Name Directives
@@ -2002,7 +2002,7 @@ seconds field includes a fractional part.
 @end table

 @node Formatting Flags
-@subsubsection Formatting Flags
+@subsection Formatting Flags

 The @samp{%m} and @samp{%d} directives support the @samp{#}, @samp{0}
 and @samp{+} flags, but the other directives do not, even if they