undo the previous commits dealing with snprintf,

use the C99 compliant function also with MS Visual Studio

src/frontend/plotting/grid.c

@@ -527,7 +527,7 @@ drawlingrid(GRAPH *graph, char *units, int spacing, int nsp, double dst, double
         if (j == 0)
             SetLinestyle(1);
 
-        snprintf(buf, sizeof(buf) - 1, "%.*f", digits + 1, m * mag / 100.0);
+        snprintf(buf, sizeof(buf), "%.*f", digits + 1, m * mag / 100.0);
 
         if (axis == x_axis)
             DevDrawText(buf, graph->viewportxoff + i -

src/include/ngspice/graph.h

@@ -17,7 +17,7 @@ Author: 1988 Jeffrey M. Hsu
 
 struct _keyed;
 
-#define GRAPH_UNITS_LENGTH  21
+#define GRAPH_UNITS_LENGTH  20
 
 /* Device-independent data structure for plots. */
 

src/include/ngspice/ngspice.h

@@ -190,7 +190,6 @@ extern double x_atanh(double);
 #define write _write
 #define strcasecmp _stricmp
 #define strncasecmp _strnicmp
-#define snprintf _snprintf
 #define isatty _isatty
 #define inline __inline
 #define popen _popen