fix 乐器维修，搜索

mec-biz/src/main/resources/config/mybatis/StudentRepairMapper.xml

@@ -210,7 +210,7 @@
                 AND sr.student_instrument_id_ = #{studentInstrumentId}
             </if>
             <if test="hasExemptionAmount != null and hasExemptionAmount ==1">
-                AND sr.exemption_amount_ > #{exemptionAmount}
+                AND sr.exemption_amount_ > 0
             </if>
             <if test="hasExemptionAmount != null and hasExemptionAmount ==0">
                 AND sr.exemption_amount_ = 0