[diagnostics] Fix table labels.

Author: jensmaurer

source/diagnostics.tex

@@ -12,9 +12,9 @@
 reporting several kinds of exceptional conditions,
 documenting program assertions, and
 a global variable for error number codes,
-as summarized in \tref{diagnostics.lib.summary}.
+as summarized in \tref{diagnostics.summary}.
 
-\begin{libsumtab}{Diagnostics library summary}{diagnostics.lib.summary}
+\begin{libsumtab}{Diagnostics library summary}{diagnostics.summary}
 \ref{std.exceptions}  & Exception classes     &   \tcode{<stdexcept>}     \\ \rowsep
 \ref{assertions}      & Assertions            &   \tcode{<cassert>}       \\ \rowsep
 \ref{errno}           & Error numbers         &   \tcode{<cerrno>}        \\ \rowsep