xpressn.c, fix semantics of `int(x)' and remove dangerous macros

int(x) most probably shall be trunc(x) instead of floor(x)
  note trunc(x) was #defined beeing floor(x)
  note ln(x) was #defined beeing log(x)

src/frontend/numparam/numparam.h

@@ -9,9 +9,6 @@
 
 /***** numparam internals ********/
 
-#define ln(x) log(x)
-#define trunc(x) floor(x)
-
 typedef enum {Nodekey = '#'} _nNodekey;  /* Introduces node symbol */
 typedef enum {Intro   = '&'} _nIntro;    /* Introduces preprocessor tokens */
 typedef enum {Comment = '*'} _nComment;  /* Spice Comment lines */

src/frontend/numparam/xpressn.c

@@ -124,8 +124,8 @@ mathfunction(int f, double z, double x)
     case 5:
         y = exp(x);
         break;
-    case 6:
-        y = ln(x);
+    case 6:                     /* ln(x) */
+        y = log(x);
         break;
     case 7:
         y = atan(x);
@@ -145,7 +145,7 @@ mathfunction(int f, double z, double x)
     case 12:
         y = MIN(x, z);
         break;
-    case 13:
+    case 13:                    /* int(x) */
         y = trunc(x);
         break;
     case 14: