Fix examples BAND _nbdr2 returning error info = -9

Both examples access the M matrix, so we initialize M to be the identity matrix. See #443 for discussion.

Author: wo80

EXAMPLES/BAND/cnbdr2.f

@@ -206,6 +206,7 @@ program cnbdr2
       idiag = kl+ku+1
       do 30 j = 1, n
          a(idiag,j) = (4.0E+0, 0.0E+0)  / h2
+         m(idiag,j) = (1.0E+0, 0.0E+0)
   30  continue
 c
 c     %-------------------------------------%

EXAMPLES/BAND/znbdr2.f

@@ -206,6 +206,7 @@ program znbdr2
       idiag = kl+ku+1
       do 30 j = 1, n
          a(idiag,j) = (4.0D+0, 0.0D+0)  / h2
+         m(idiag,j) = (1.0D+0, 0.0D+0)
   30  continue
 c
 c     %-------------------------------------%