fix undefined reference to 'blis_abort'

see https://github.com/flame/blis/issues/428 + https://github.com/flame/blis/pull/429

--- blis-2.2.orig/frame/base/bli_error.h	2020-12-07 19:40:33.936990613 +0100
+++ blis-2.2/frame/base/bli_error.h	2020-12-07 19:45:35.079406108 +0100
@@ -40,6 +40,7 @@
 
 void      bli_print_msg( char* str, char* file, guint_t line );
 void      bli_abort( void );
+BLIS_EXPORT_BLIS void      bli_abort( void );
 
 char*     bli_error_string_for_code( gint_t code );
 
