Correcting the ESMF link path in src/core_atmosphere/utils/Makefile

This commit corrects the link path for the ESMF module by replacing the
incorrect make variable MPAS_ESMF_LIBS with MPAS_ESMF_LIB, which is the
variable defined in the root Makefile.

This issue came to attention due to a linking error that arises when building
the MPAS atmosphere core with the nvhpc compiler in DEBUG mode.

Author: abishekg7

src/core_atmosphere/utils/Makefile

@@ -7,7 +7,7 @@ endif
 all: $(UTILS)
 
 build_tables: build_tables.o atmphys_build_tables_thompson.o
-	$(LINKER) $(LDFLAGS) -o build_tables build_tables.o atmphys_build_tables_thompson.o -L../../framework -L../physics -lphys -lframework $(LIBS) $(MPAS_ESMF_LIBS)
+	$(LINKER) $(LDFLAGS) -o build_tables build_tables.o atmphys_build_tables_thompson.o -L../../framework -L../physics -lphys -lframework $(LIBS) $(MPAS_ESMF_LIB)
 	mv build_tables ../../..