regress: make minimum number of samples for regression public

regress.c

@@ -209,8 +209,6 @@ n_runs_from_residuals(double *resid, int n)
 /* Return a boolean indicating whether we had enough points for
    regression */
 
-#define MIN_SAMPLES_FOR_REGRESS 3
-
 int
 RGR_FindBestRegression 
 (double *x,                     /* independent variable */

regress.h

@@ -66,6 +66,9 @@ extern double RGR_GetChi2Coef(int dof);
    points */
 #define REGRESS_RUNS_RATIO 2
 
+/* Minimum number of samples for regression */
+#define MIN_SAMPLES_FOR_REGRESS 3
+
 /* Return a status indicating whether there were enough points to
    carry out the regression */