[svn-r16829] Bug fix.

In Up (AIX system), the insert_libhdf5_settings() infinite looped because
it never found EOF.  Man getc in another system said:
   "If  the  integer  value returned by getc() is stored into a variable of
   type char and then compared against the integer constant EOF, the  com-
   parison may never succeed, because sign-extension of a variable of type
   char on widening to integer is implementation-defined."

Solution:
Changed inchar from type char to int fixed the problem.
Morale of the story: RTFM or HTCW (heed the compiler warnings).

Tested:
Up (AIX 5.3).

src/H5detect.c

@@ -522,7 +522,7 @@ static void
 insert_libhdf5_settings(void)
 {
     FILE *fsettings;
-    char inchar;
+    int inchar;
     int	bol=0;	/* indicates the beginning of a new line */
 
     if (NULL==(fsettings=HDfopen(LIBSETTINGSFNAME, "r"))){