[eguile-utilities] fmtnumeric displays decimal instead of fraction

previously fmtnumeric would convert gnc_numeric to double. simplifying
the code had omitted this conversion, and exact fractions were
rendered. ensure decimal is rendered.

gnucash/report/report-system/eguile-utilities.scm

@@ -39,7 +39,8 @@
   (number->string (if (integer? n) (inexact->exact n) n)))
 
 ;; Format gnc-numeric n with as many decimal places as required
-(define-public fmtnumeric fmtnumber)
+(define-public fmtnumeric
+  (compose fmtnumber exact->inexact))
 
 (define-public (gnc-monetary-neg? monetary)
   ; return true if the monetary value is negative