fix compilation

Author: Antonov548

src/rinterface_extra.c

@@ -8346,8 +8346,8 @@ SEXP R_igraph_power_law_fit_new(SEXP data, SEXP xmin, SEXP force_continuous, SEX
   c_xmin = REAL(xmin)[0];
   IGRAPH_R_CHECK_BOOL(force_continuous);
   c_force_continuous = LOGICAL(force_continuous)[0];
-  IGRAPH_R_CHECK_BOOL(pvalue);
-  c_compute_pvalue = LOGICAL(pvalue)[0];
+  IGRAPH_R_CHECK_BOOL(compute_pvalue);
+  c_compute_pvalue = LOGICAL(compute_pvalue)[0];
 
   IGRAPH_R_CHECK(igraph_power_law_fit(&c_data, &c_res, c_xmin, c_force_continuous));